C/EBPβ对心房肌细胞KCNQ1基因表达的调控作用研究

The regulatory effect of C/EBPβon KCNQ1 gene expression in atrial myocytes

目的探讨CCAAT/增强子结合蛋白β(C/EBPβ)对心房肌细胞KCNQ1基因表达的调控作用。方法利用生物信息分析和转录因子筛选板筛选出C/EBPβ作为KCNQ1的转录因子。用5-Hz电刺激快速起搏心房肌细胞。用染色质免疫沉淀法检测C/EBPβ、KCNQ1 m RNA和蛋白的表达水平。将心房肌细胞转染慢病毒并分为对照组、C/EBPβ抑制组和过表达组,采用荧光定量PCR和蛋白质印迹技术检测KCNQ1的表达水平;采用膜片钳测定Iks膜电位和电流峰值。结果C/EBPβ参与了KCNQ1的转录,心房肌细胞中C/EBPβ、KCNQ1 m RNA和蛋白的表达水平快速起搏下显著高于非快速起搏下(均P<0.05)。与对照组比较,C/EBPβ抑制组KCNQ1 m RNA表达和Iks电流显著降低而C/EBPβ过表达组显著升高(均P<0.05)。结论C/EBPβ可能对心房肌细胞KCNQ1基因的表达有调控作用。

Objective To explore the regulatory effect of CCAAT/enhancer binding protein beta(C/EBPβ)on KCNQ1 gene expression in atrial myocytes.Methods C/EBPβwas selected as a transcription factor for KCNQ1 by using bioinformatics analysis and TF Activation Profiling Plate Array.Rapid pacing of atrial myocytes was achieved by5-Hz electrical stimulation.Chromatin immunoprecipitation was used to detect the expression levels of C/EBPβ,KCNQ1m RNA and protein.Atrial myocytes were transfected with lentivirus and divided into control group,C/EBPβinhibition group and overexpression group.The expression level of KCNQ1 was detected by fluorescence quantitative PCR and Western blotting.Membrane potential and peak current of Ikswere measured by patch clamp technique.Results C/EBPβwas involved in the transcription of KCNQ1.The expression levels of C/EBPβ,KCNQ1 m RNA and protein were significantly higher in atrial myocytes in the presence of rapid pacing than in the absence of rapid pacing(all P<0.05).Compared with the control group,KCNQ1 m RNA and Ikscurrent decreased significantly in C/EBPβinhibition group and increased significantly in C/EBPβoverexpression group(all P<0.05).Conclusion C/EBPβmay have regulatory effect on KCNQ1 gene expression of atrial myocytes.